I have a slow filling well and I want to install a 1200 gallon holding tank. I am not sure what the safest way to disinfect it is. My plan is to bury a plastic tank install some type of pump control system for water collection, draw from the reserve, and let the tank refill throughout the day and into night. My concern is bacteria. I have a filter system and a UV light where the water goes into the house but is this all that I need. Any information is appreciated.

Thanks.
Jason